by Barbara Gardener (Holliston Garden Club)

Ever since I’ve read two tree bestsellers during the pandemic – Richard Powers’s 2019 “Overstory” and German forester Peter Wholleben’s “The Hidden Life of Trees”, trees have taken on a whole new and marvelously mysterious significance.  I notice and appreciate them in an entirely new, organic and exciting way – how old are they, how tall are they, how are they communicating with each other and the rest of the natural world in this very moment, how many organisms are feeding off their roots and do they breathe all day and all night?  These thoughts monopolize me as I walk under their cover and through the forest or landscape. This examination has led me to question why we’re always talking about the importance of just native plants but rarely discuss or promote the importance of native trees.

A native tree is a species that was growing here before the arrival of Europeans and before the introduction of invasive species of trees like Norway maples or Buckthorns which have seriously dwindled the number of standing native trees.  Reintroducing native species of trees and shrubs helps to re-establish the original eco-system of the region and improves their chances for survival and, by extension, all the critters that depend on their unique and local properties.  

Native trees are a perfect fit for our specialized environment – they are happier here than their non-native counterparts and consequently require less water and fertilizer and have built up natural defenses to counter pests and fungal infections.  All of these reasons translate into a lower cost of maintenance for the homeowner.

Long living trees like native oaks and maples are very effective at soaking up greenhouse gases.  They absorb airborne pollutants such as carbon dioxide, ozone, carbon monoxide, and sulfur dioxide.

Trees breathe by releasing moisture into the air and cool the air by spreading the sun’s rays.  Shade trees keep our lawns greener longer which in turn requires less water.  Reforestation of urban heat islands with native trees now covered in asphalt is one of the most important ways to mitigate the kind of excessive heat we have experienced here and throughout the country in June of this year.  Trees are natural regulators of heat and cold, shading and cooling our homes throughout the summer and, depending on placement, acting as a wind break, lowering heating costs in the winter.

Many species of wildlife do not recognize non-natives species and cannot use them for food or shelter. Native trees and shrubs are especially important to all forms of native wildlife, including birds, mammals, and insects.  Just think about it – they are a resource for nesting, fruit and leaves for food, shelter from prey, height for safety and shade for comfort and protection.  Trees support the lives of hundreds of organisms in a complicated network that cannot be duplicated in commercially planted environments.

Carol Stocker, long time and respected garden columnist for the Boston Globe, admits, “A mature native tree is more valuable than anything I can plant…though native asters, sunflowers and goldenrod are good providers, trees are the true heroes…”.  She cautions all of us to do a better job preserving them – developers should think again before they clear cut century old stands of native trees for convenience’s sake, home gardeners should not cut down native trees to expand their lawns or plant non-native species because they are pretty as opposed to the right choice for our local ecosystems or cut down a native shade tree because it’s encroaching on their flower beds.

Given their essential nature, isn’t it time we re-examined how we treat native trees?